Michigan Compiled Laws, Chapter 339. Occupational Code § 339.918

Sec. 918.  (1) Within 5 days after the initial communication with a consumer in connection with a collection of a debt, a collection agency shall send the consumer, unless the following information is contained in the initial communication or the consumer has paid the debt, a written notice containing all of the following information:

(2) If the consumer notifies the collection agency in writing, within 30 days after receiving the written notice, that the debt, or any portion of the debt, is disputed, collection of the debt or any disputed portion of the debt shall cease until the collection agency obtains verification of the debt and a copy of the verification or judgment is mailed to the consumer by the collection agency.  Verification of the debt or any disputed portion of the debt shall include the number and amount of previously made payments and the name and address of the original creditor, if different from the current creditor, or a copy of the judgment against the debtor.

(3) The failure of a consumer to dispute the validity of a debt under this section shall not be construed as an admission of liability by the consumer.